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| author | Zeex <zeex@rocketmail.com> | 2018-09-06 23:17:54 +0600 |
|---|---|---|
| committer | Zeex <zeex@rocketmail.com> | 2018-09-06 23:18:07 +0600 |
| commit | b6226952edf11318b7bb8c0e6d7994ddce8e7ca2 (patch) | |
| tree | d8e5d1c5379bdb222f72ed9230088be7ec812906 /subhook_x86.c | |
| parent | 753673f7f71ccd285d90d725996e0e4dea3c51ce (diff) | |
| download | subhook-b6226952edf11318b7bb8c0e6d7994ddce8e7ca2.zip subhook-b6226952edf11318b7bb8c0e6d7994ddce8e7ca2.tar.gz subhook-b6226952edf11318b7bb8c0e6d7994ddce8e7ca2.tar.bz2 | |
Don't check for jmp offset overflow in 32-bit build (#33)
Diffstat (limited to 'subhook_x86.c')
| -rw-r--r-- | subhook_x86.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/subhook_x86.c b/subhook_x86.c index 909e900..549225c 100644 --- a/subhook_x86.c +++ b/subhook_x86.c @@ -50,6 +50,7 @@ #include <stdint.h> #endif +#define ABS(x) ((x) > 0 ? (x) : (-(x))) #define MAX_INSN_LEN 15 /* maximum length of x86 instruction */ #define JMP_OPCODE 0xE9 @@ -280,16 +281,15 @@ static int subhook_make_jmp32(void *src, void *dst) { struct subhook_jmp32 *jmp = (struct subhook_jmp32 *)src; intptr_t src_addr = (intptr_t)src; intptr_t dst_addr = (intptr_t)dst; - int64_t distance; +#ifdef SUBHOOK_X86_64 + int64_t distance = ABS(src_addr - dst_addr); +#endif - if (src_addr > dst_addr) { - distance = src_addr - dst_addr; - } else { - distance = dst_addr - src_addr; - } +#ifdef SUBHOOK_X86_64 if (distance < INT32_MIN || distance > INT32_MAX) { return -EOVERFLOW; } +#endif jmp->opcode = JMP_OPCODE; jmp->offset = (int32_t)(dst_addr - (src_addr + sizeof(*jmp))); |